Pressure regulating valve for fuel injection systems

Abstract

There is proposed a pressure regulating valve for a fuel injection system which serves to regulate the heating-up fuel amount for an explosion, external auto-ignition, internal combustion engine. The pressure regulating valve comprises a movable valve component which is urged in the closing direction by a pressure spring which during the heating-up phase acts against a temperature responsive element which in turn acts with a force that can be influenced by another temperature responsive electrically heatable element so that during the heating-up phase the air-fuel mixture can be proportioned in accordance with the requirements of each internal combustion engine.

What is claimed is: 
     
       1. A pressure regulating valve for a fuel injection system for a mixture-compressing, externally ignited, internal combustion engine having a suction duct including an air-flow sensor member which is displaced by the amount of air flowing through it against the restoring force produced by a pressure fluid, said pressure fluid being continuously conveyed to a control pressure conduit under constant pressure and changeable at will by means of said pressure regulating valve, said pressure regulating valve further including a movable valve component one side of which is under the action of said pressure fluid and the other side thereof being under the action of a pressure spring with the force of the pressure spring being decreasable by a first temperature-responsive element further characterized in that a second temperature responsive element is arranged in said pressure regulating valve for engagement with said first temperature-responsive element so that said second temperature-responsive element acts in the direction of reducing the force of said first temperature-responsive element on the pressure spring. 
     
     
       2. A pressure regulating valve as claimed in claim 1, further characterized in that an electrical heating coil is associated with said further temperature-responsive element and the circuit of the coil being closed by the ignition and start switches of the internal combustion engine. 
     
     
       3. A pressure regulating valve as claimed in claim 2, further characterized in that said temperature responsive elements comprise bimetallic spring means. 
     
     
       4. A pressure regulating valve as claimed in claim 3, characterized in that said first bimetallic spring means and said second bimetallic spring means have an adjustable insert interposed therebetween. 
     
     
       5. A pressure regulating valve as claimed in claim 4, further characterized in that said first and said second bimetallic spring means are arranged to cooperate with a transmission spring with said first and second bimetallic spring means being in contact above a predetermined temperature by means of said adjustable insert.